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Table 2 Formulas to calculate the raw scores

From: Validation of undergraduate medical student script concordance test (SCT) scores on the clinical assessment of the acute abdomen

Scaletype

Method

Score

AGG

Aggregate

p i  = n i /n mode

AGGPEN

Wilson’s aggregate with distance penalty

p i  = (pAGG i  + pDMODE i )/2

DMODE

Distance to mode

p i  = 1 − abs(imode − i) * 1/d max with d max  = 4 for 5-point Likert scales

DMEAN

Distance to mean

p i  = 1 − (abs(ī − i) * 1/d max with d max  = 4 for 5-point Likert scales

SBA

Single best answer

\( {p}_i=\left\{\begin{array}{cc}\hfill 1\hfill & \hfill \mathrm{f}\mathrm{o}\mathrm{r}\ {i}_{mode}\hfill \\ {}\hfill 0\hfill & \hfill \mathrm{else}\hfill \end{array}\right. \)

normalization

Z-transformation expertscale on (80, 5)

\( {\overline{p}}_{trans}=80+\left({\overline{p}}_{raw}-mea{n}_{exp}\right)/s{d}_{exp}*5\Big) \)